D&D 5E (2014) Clerics vs Druids in an Animist Setting

[SheWantstheD&D]

Clerics choose the spirit they follow; Warlocks are chosen by a particular spirit?
Most likely a (Fey) trickster type, mischievous more than wicked. Coyote for example.

(I love your username)

 

[transtemporal]

But, what differentiates Clerics from Druids in a world like this, especially Nature Clerics and Land Druids.

Disagreeing on the appearance or name or creation myth is enough to differentiate the faiths, even if they are exactly the same underneath. The powerset could be identical.